They don't seem to just be holdovers from previous games either because they're often different than the listed abilities for the same pokemon from previous games, and there are listed abilities for pokemon that only appear in Legends: Arceus as well. But no pokemon in Legends: Arceus have abilities.
Abilities for all Pokemon in Legends: Arceus, including the new Pokemon, were found in the game files during the datamine. They exist but are not usable in Legends: Arceus.
All Pokemon sites are listing the abilities, not just PokemonDB.
